it drops the rest
who/what is it though?
Arguably it’s you, right, because you supplied two arguments instead of one
If you are entering that command in bash, then, yes, a backslash does make bash treat it like a literal space character as opposed to a delimiter for the arguments, and if that didn’t do it then I start wondering what you entered and what “seems” means, maybe it even succeeded.
%20 will not help you, because those are perfectly valid characters on their own, nothing special happens with that.
quoting your argument will also treat it as a single argument
renaming directories is not the only other option, you can just as well use a different directory, or for that matter change your current directory to that directory
There’s also a whole lot of silliness of back and forth between windows and a more unix-like environment going on there, normal usage looks like so:
$ sqlite3 mydatabasefile
since you’re passing those arguments to some program named winpty, it is possible that it doesn’t deal correctly with spaces. if that’s the case, and I’m not saying it is, then the path of least resistance would be to use directories without spaces in them, though the real solution is to use fewer odd workarounds and eliminate the things being worked around
if you’re going to use an sqlite executable compiled for windows then you might want to use a terminal application for windows too, like powershell, or install sqlite3 in whatever environment you’re using bash in
you could also use a virtual machine and run linux to avoid having to deal with workarounds in windows which are more difficult than the task itself